Five Questions: Sean Astin

Actor Sean Astin, known for his portrayal of Samwise Gamgee in "The… (Michael Robinson Chavez,…)

Actor Sean Astin — a.k.a. Samwise Gamgee in "The Lord of the Rings" — trekked across much of Middle-earth wearing hairy prosthetic feet.

It's easy to be motivated with a legion of orcs on your tail. But on the streets of Los Angeles on regular old Earth, Astin must find the drive to run from within. On March 18, Astin ran the L.A. Marathon for the third time — but as he explained in a recent interview, he doesn't always find it easy to push himself to lace up those shoes.

Tell me how you got into running.

I was about 14, and my friend's stepdad asked me to do a 10K with him because his son — who was more into basketball — didn't want to. It was amazing, and I still remember the time I got: 48:23.

Later, I ran cross-country for Crossroads School in Santa Monica. I really wanted a varsity letterman jacket, but you had to be in the top seven to race. I was ninth. But one guy got sick and another was hit by a car [he wasn't badly hurt], and I snuck my way in.

After high school, it became a lot more sporadic. I would run around UCLA sometimes and occasionally see a sign for a 10K race and register for that, but I wasn't that dedicated.

From 2007 to now, I have every single run recorded on my Nike Plus system. I've noticed a definite pattern to my running, where I'll go for two months without a single run, and then I'll run 20 miles in a month, and then 100 miles the next month, then 120 the months after that, then work my way back down to nothing again.

That's kind of a bizarre approach to training. What's going on here?

I'm not sure why I'm doing it. If you look at photos of me during the months off, I'm 20 pounds fatter, and at the peak I'm skinny. It's an unhealthy pattern, and I've tried to figure it out.

My diet is always terrible, unfortunately. I don't know moderation. I kind of peak at how far I can push my body, and then I run out of determination for the habit and start easing off. It's really just a lack of focus and discipline.

There are always a couple of months in the year when I'm really sloth-like, but when I'm on the upswing, you pass a certain threshold … where the addiction comes back. Then it's off to the races.

When you're not running, do you miss it?

I'm much more prone to feeling down a lot. I just feel sluggish and unmotivated. You feel like you'll never get back to it, and that's just awful. It takes time to evolve out of it.

There is a bottom where my mind will start gearing itself up again. My mind knows that once it starts, it's going to go hard. The amazing thing is, you're one short run away from feeling like you're moving in the right direction. Something about the blood moving makes you feel better.

I think I am getting better at minimizing periods of inactivity. At 41 now, it takes almost no time to get out of shape and fat. And it takes longer to get back into shape. So a self-preservation instinct kicks in where you just don't want to do that hard work again. You just want to do the hard work of maintaining it instead.

Tell me about your marathon experiences.

This was my third, and they were all L.A. Marathons. My first was 1998, with a time of 4:04. I did 2010 but on a torn calf muscle, and my time was 5:16. It was a miracle I was able to run it. For 2012, my time was 4:25, and I feel it's not representative of what I'm capable of. I came out of the box too fast and never once was I comfortable during the race.

I am determined to get a sub-four-hour marathon. I want to do this by next year.

Being as you played Sam Gamgee, I have to ask: What's your opinion on barefoot running?

I saw a lot of people running barefoot in the L.A. Marathon, and it looks to me like it would be really hard. I wouldn't be a big proponent of it. I just don't think it would be a good thing for me to do.